1. Field of the Invention
The present invention relates to a vehicle control device.
2. Description of the Related Art
Japanese Patent Application Publication No. 9-322311 (JP 9-322311 A), for example, describes a vehicle control device according to the related art that is provided in a vehicle to control rotation of a motor that generates a drive force on a drive shaft that transmits torque to drive wheels. In the vehicle control device, motors such as a clutch motor and an assist motor are controlled to control torque to be transferred to the drive wheels.
In a vehicle control device such as that according to JP 9-322311 A, a target value is derived so that torque that corresponds to the amount by which a driver depresses an accelerator pedal is output as described in relation to control during rearward travel of a vehicle. A torque command value is set in accordance with the derived target value so as to cause the clutch motor and the assist motor to output torque.
In some cases, torque transferred from each motor to the drive wheels passes through a drive unit that includes a speed reducer. The drive unit includes a plurality of gears rotatably supported by a plurality of bearings, and a load acts on the bearings because of rotation of the gears when the vehicle travels forward or rearward.
If the vehicle control device according to JP 9-322311 A is applied to the drive unit, the difference between maximum torque required during forward travel of the vehicle and maximum torque required during rearward travel of the vehicle is not taken into consideration in deriving the target value. Thus, a load is applied to the bearings constituting the drive unit in the same manner irrespective of whether the vehicle is traveling forward or rearward, which is disadvantageous in terms of extending the life of the bearings of the drive unit.